Wall and building structure



May 11, 194s,

H. G. PILLSBURY ETAL WALL AND BUILDING STRUCTURE Fi le d March 27, 1941E\-a il 1 FIG-3 FIG-4 2 Sheets-Sheet l rFw FIG-5 l HOWARD cl 'gou 5..INGERSOLL NVENTORS G. PILLSBURY ATTO R N EY Patented May 11, 1943 UNITEW'ALL AND BUILDING STRUCTURE Howard G. Pillsbury and Elton B. Ingersoll,De-

troit, Mich, assignors to Chamberlin Metal Weather Strip Company,Detroit, Mich., a corporation of Michigan Application March 27, 1941,Serial No. 385,403

3 Claims.

The invention relates to a fireproof Wall construction. It relates moreparticularly to a structure of this nature to be used for walls,partitions and ceilings in buildings devoted to the manufacture,storage, or handling of materials which constitute an explosion or firehazard.

As is well known to those who have made extensive studies in themechanics of the origination, propagation, and prevention of explosions,a rigid Wall structure or partition affords little or no protection incase of explosion, unless of course the wall is made so thick and strongas to make its cost generally prohibitive. In the usual explosion allretaining, rigid partitions shatter immediately and the injuriouseffects incident on the explosion, such as the usuall accompanying fire,are communicated to adjoining chambers.

We have devised a wall structure which is, to a high degree, fireproof,and which offers a resiliently yielding barrier to explosions. We havefound, by actual tests under explosive conditions, that the wallstructure hereinafter to be described is much more resistant to thedestructive effects of explosions than is the usual rigid wallconstruction, and the flame resistance of our wall material is so high,and its heat conductivity is so low, that it prevents fire transmissiontherethrough to a surprising extent, in view of the simplicity andeconomy of the structure.

We have used, in combination with our fireproof wall construction, anexterior wall assembly such as is described and claimed in a copendingapplication of Elton B. Ingersoll and Leon E. Willett, Serial No.385,402 filed of even date herewith. The advantage of this combinationwill become more fully apparent as the description proceeds, but,briefly, we have provided an exterior wall of sturdy construction andlight weight, and assembled from spaced panels of translucent materialwhich is substantially shatterproof. As more fully described hereinbelowand in the aforesaid copending application, this exterior wall structureis an excellent heat insulator and withstands ordinary shocks, butserves more or less as a safety valve in severe explosions, since ityields or blows out more readily than the fireproof interior wallstructure mentioned in preceding paragraphs. We therefore prefer to useour spaced panels of translucent material in exterior walls so thatexplosive forces may be dissipated into the outer air, whereas in theinterior partitions and ceiling we use the stronger and more flameresistant wall structure so as, in

effect, to direct the explosive forces in a desired direction.

While the invention disclosed herein may be embodied in a variety offorms, differing only in detail, and not in essence, we have chosen forillustration several embodiments which are to be regarded as exemplary,and not limiting.

In the drawings, Fig. 1 shows in elevation, and partly broken away,several adjacent panels, in edge abutting relationship in a partitionwall or ceiling, and constructed and assembled in fire resistantrelationship in accordance with the present invention.

Fig. 2 is a fragmentary perspective view, partly in section, of aportion of Fig. 1 showing details of construction at the meeting edgesof adjoining panels.

Fig. 3 is a fragmentary sectional view of a fireproof panel edgeassembly, three layers being shown in laminated contact.

Fig. 4 is a fragmentary sectional view of a fireproof panel edgeassembly, showing one method of assembling a two-ply fireproof panel,the components being spaced somewhat apart in parallel planes.

Fig. 5 is a fragmentary sectional view of a fireproof panel edgeassembly, generally similar to Fig. 4, but showing a somewhat differentmethod of gripping the edges.

Fig. 6 is an enlarged, fragmentary sectional view, showing a singlefireproof layer.

Fig. 7 is an enlarged fragmentary sectional View showing still anothermethod of gripping the panel edges.

Fig. 8 is an enlarged fragmentary sectional view showing yet anothermethod of gripping the panel end edges.

Fig. 9 is a perspective view, partially broken away, of a chamberstructure showing interior partitions and ceiling, and exterior wall androof to illustrate our preferred construction wherein the interiorpartitions and ceiling are fireproof and resiliently resistant toexplosion pressure, whereas the exterior wall is weaker or lessresistant to explosion pressure.

Fig. 10 is a fragmentary section, somewhat enlarged, and taken on theline Ill-40 of Fig. 9.

Fig. 11 is a fragmentary section, similar to Fig. 10, but showing aslightly modified form of the invention.

Fig. 12 is a fragmentary section, somewhat enlarged, of a translucent,shatterproof sheet as used in the outer wall construction.

Before the present invention is described i detail, it is to beunderstood that such invention is not limited to the details ofconstruction and/or the specific arrangement of parts herein illustratedand/or described, as the invention obviously may take other forms. Italso is to be understood that the phraseology or terminology hereinemployed is for the purpose of description and not of limitation.

We will first describe the fireproof panel unit which may be usedwherever convenient or desirable, even in exterior wall construction,although preferred for interior walls. We will thereafter describe theuse of this fireproof construction for interior partitions and ceilingsin conjunction with an exterior wall of translucent, shatterproof,relatively frangible material. As used herein we comprehend, by the termshatterproof, a material which will not fly in splinters like ordinaryglass, but a yieldable material which will not splinter or fly infragments though it may rip or tear under severe explosive forces.

Our fireproof wall structure (Figs. 1 to 8) has as its basic element alayer or sheet of screen wire, or metallic mesh fabric, which screen isused as a resilient supporting framework or skeleton o for a more orless impermeable layer of fireproof material. While a variety ofrefractory materials is available, we prefer to use a fibrouscomposition of matter which, in preliminary stages,

is quite plastic, and which may be applied to the supporting andstrengthening screen with a brush or trowel, or in any suitable manner.

Such a material is available commercially under the general designationof rock wool cement, and consists of finely ground rock wool fibercarried in a tacky binder. While this cement may be used as so procured,we prefer to add thereto a certain proportion of desiccated asbestosfiber. One such composition which we have found very suitable is made upfrom about two parts of rock wool cement to one part of desiccatedasbestos. This is preferably applied on one or both sides of asupporting screen and allowed to dry. It dries to a flat surface, isrelatively crackproof, and is highly resistant to destruction by shook.It is impermeable to ordinary fiame attack and its heat conductivity isextremely low. I

As a strengthening and supporting element for our wall structure we haveused a 12-mesh screen of stainless steel wire of 0.028 inch in diameter.This has a. high tensile strength and ductility and provides thefireproof panel with exceptional shock resistance. Another supportingscreen which we have found very suitable is a 14-mesh screen ofgalvanized steel wire of 0.022 inch diameter.

While a panel composed of a single layer as above described affordssubstantial protection against both fire and explosion, we have providedassembled wall structures comprising two or more laminations injuxtaposed relationship. Each lamination is preferably composed of ascreen impregnated with fireproof material. The juxtaposed laminationsmay be actually in contact with each other, or they may be spaced apart,for instance, one-half or one-quarter of an inch. When the laminationsare in contact, or in close juxtaposition, an explosive force mustrupture the wire of all laminations simultaneously, so that a wall soformed is stronger, or offers greater resistance to explosive forces,than one whose laminations are spaced, and it is therefore more suitablefor interior walls. While an interstitial air space affords excellentheat installation and shock-cushioning protection, we may fill thisspace with a fireproof plastic material of the nature already described.Two or more laminations either coated and in close juxtaposition, orspaced, with fireproof material packed therebetween, afford a highdegree of fire prevention and represent the most efficient protectionagainst the destructive effects of explosion.

We have shown, in Figs. 1 to 8, several embodiments of fireproof wallelements, and one method of assembling adjacent fireproof panels in edgeabutment. Referring first to Figs. 1 and 2, we show, in Fig. 1, threepanels In of fireproof nature as described, maintained in edge abutmentby any suitable means such as a conventional retaining frameconstruction H fixed in place by floor or ceiling brackets l2. Eachpanel [0, in the embodiment shown in Figs. 1 and 2, is assembled fromtwo or more closely juxtaposed laminations l3 and M. The peripheraledges of the said laminations l3 and I4 diverge from each other so as tobe lapped around stiffeners l5 and I6 respectively. A conventionalchannel member having a base I! and upturned flanges l8 and I9 serves asa retaining seat for the edges of the laminations, when assembled asdescribed, and the complete panel assembly, with sheathed edges asshown, is assembled in the manner illustrated in detail in Fig. 2.Spaced rivets or bolts 20 are used to make a unitary, compact, panelassembly.

In the embodiment shown in Fig. 3 we have illustrated fireproof assemblyof three-ply form. Here, two laminations 2| and 22 are attached at theirperipheral edges as previously described but diverging somewhatthroughout their exposed surface to permit the inclusion therebetween ofa third lamination 23 which increases the heat resistance, shockabsorption characteristics, and general strength and resiliency of thepanel. In an actual construction of this type we have used for thecenter lamination 23 a galvanized steel Wire screen impregnated withfireproof material, and for the two outer laminations 2| and 22 astainless steel screen similarly impregnated. While the panel 23, asshown, is retained merely by the pressure of panels 2| and 22, it may ofcourse have its peripheral edge portion extended so as to be heldbetween the stiffening strips 24.

Figs. 4 and 5 illustrate still another embodi ment of our invention. Inthis embodiment a spacing strip 26 is placed between the edge portionsof laminations 21, 28. In Fig. 4 the edges are shown as being mutuallyoverlapped around the spacing strip 26 and in Fig. 5 the edges areoutturned over the stiifeners 29 and 30. In each case the laminations 21and 28 are spaced apart a substantial distance, for instance one-halfinch, and while an inert air space therebetween may serve as a quiteadequate shock cushion and heat insulator, we have found that still moresatisfactory construction is achieved by packing the interstitial spacewith fireproof plastic material of the nature already described. Butwith the wire laminations spaced, the wall is not so strong as thatshown in Figs. 2 and 3, and is more suitable for an exterior wall.

Fig. 6 shows, in section, and somewhat enlarged, a fireproof panel suchas previously indicated in the various embodiments byreference numeralsl3, [4, 2|, 22, 23, 27 or 28. The wire mesh 3! is embedded in thefireproof coating 32, but the over-all thickness of the panel as a wholeis not materially greater than the thickness of the uncoated wire mesh.

Fig. 7 shows in section, and somewhat enlarged, a fireproof panelcomprising four sheets of fireproof material 45, constructedas-previously de-'- scribed, and gripped at their peripheraledgeportions by a channel member 46, to which they are firmly attachedby some suitable means such as rivet 41. Since in many applications acompact, neat, and dustproof assembly is desired, the structure shown inFig. 7 meets these requirements.

Fig. 8 shows in section, and somewhat enlarged another method ofassembly for a fireproof panel comprising a plurality of laminations.Instead of using assembled, separate sheets such as shown in previousfigures, Fig. 8 shows a single sheet 48 folded successively back andforth upon itself so as to provide a plurality of adjacent end folds 49overlapped in the manner shown. This construction results in anappreciable increase in thickness at the folding zone, and enables us toapply a channel member 50 having side flanges which have a convergingtaper as shown. When secured by spaced rivets 52, the grip isexceedingly tight and secure.

Extensive tests have been made by constructing special chambers havingwall portions made up from panels of one or other of the embodiments sofar discussed. Severe explosions have been generated within the chambersand the panels have withstood the destructive tendencies of theexplosion in very favorable contrast to failures in solid panels testedsimultaneously. This is especially true of panels comprising two or morelaminations in close juxtaposition. In the latter instances we havedirected blow torch flames against one lamination for an extendedperiod, thereby raising the temperature of the supporting metallic meshscreen to a visual red heat, without appreciable effect on theneighboring superposed lamination and without raising the temperature ofsaid neighboring lamination to a point which would induce combustioneven in turpentine soaked paper placed in contact therewith. Panelsconstructed as described have sometimes warped slightly under intenseheat (and returned practically to normal contour on cooling), and theyhave yielded somewhat when bounding an inclosure within which anexplosion has occurred, but they have nevertheless maintained anintegral continuity without tearing or shattering.

One-ply panels, or a plurality of laminations in close juxtaposition asdescribed, are recommended for ceilings and interior walls of chamberswhere it is desirable that the effect of a fire or explosion beprevented from spreading to adjoining chambers. They are particularlyadvantageous in factories which are manufacturing munitions andexplosives, and also in plants engaged in the production of metallicpowders which frequently unite violently with oxygen. Panels such as wehave described may be finished to a very'smooth surface on which paintmay be quite satisfactorily applied, and the acoustical properties ofpaneled walls of this naskiled in the metallurgical arts, by increase inthe wire diameter, or change in the alloy, or by various thermaltreatments or otherwise. It is like wise obvious that a number ofsuitable fireproof mixtures are available, or may hereafter bedeveloped, which can be applied in some convenient manner to thestrengthening screen.

The screen is preferably of a fine enough mesh to serve as an adequateskeleton structure to per-' manently retain the fibrous fireproofingmaterial. Fine mesh is also desirable because it reduces the diameter ofthe wire and hence the over-all thickness of the screen. Y

While we have shown a method of mounting the panels in a more or lessrigid supporting frame structure, it is obvious that the generalresiliency of the wall could be improved by mounting each individualpanel assembly in a spring supported frame such as is coming into usefor absorption of shock, accidental or intentional, in retaining guardscreens, for instance in psychiatric institutions.

Figs. 9 to 12 illustrate a fireproof interior partition and ceilingstructure, such as has been described above, in combination with anexterior wall of translucent, shatterproof structure which yields orfractures somewhat more readily than the wall structures described inconnection with Figs. 2 and 3, on account of the difference in thestrength, or manner of resistance, of the coating material. Since,generally speaking, an explosion will do less damage if allowed toexpand its force through an outer wall into the open air than if theexpanding gases break through partitions into adjoining chambers, wehave here and in Figs. 4 and 5 provided an outer wall which, in safetyvalve fashion, gives way immediately upon a serious explosion so as toprotect the other interior walls of the chamber and restrict the effectof an explosion to a definite or desired point of exit.

Fig. 9 shows, in perspective from an elevated viewpoint, a chamberhaving interior partition walls and ceiling assembled from relativelystrong panel units 33 such as hereinabove described. The weaker safetywall is built up from shatterproof, translucent units 34 such as aremore fully described and claimed in the said copending application,Serial No. 385,402, filed of even date herewith, and above referred to.Referring more particularly to Fig. 10, an outer wall unit 34 consistsof two juxtaposed panel carrying frames 35, 35, each frame carrying asheet of translucent material firmly united to the frame at 31, 38respectively, so as to provide an inert air space 39 therebetween. Thesheet is preferably of shatterproof plastic material 40 (Fig. 12) havingimbedded therein a strengthening mesh 4|. A material of this nature andof physical charteristics satisfactory for my purpose is commerciallyavailable under the trade name Cel-O- Glass. A completed wall unitpreferably comprises at least two such sheets retained in compactassembly, for instance in the manner shown in Fig. 10.

We have illustrated, in Fig. 11, a further shatterproof assemblycomprising Cel-O-Glass sheets 42 and 43 in combination with a sheet offine mesh wire screen 44 such as used, for example, on the Davy safetylamp. A screen of this nature is impervious to ordinary tongues of flameunless the screen is subjected to a general and continuous fire at atemperature suflicient to melt the wires thereof. This fire screen is,of course, permeable to outrushing, expanding gases, and does notdetract from the safety blow-out features of our invention. AdjoiningWall units may be abutted in edge-to-edge relationship as shown in Fig.10 or in any other suitable Way. Injured panels are readily repaired bysubstituting a new Cel-O-Glass sheet for the injured one, or byreplacing the complete unit which is readily removable from thesupporting frame.

What we claim is:

1. A wall panel for a chamber where explosives are stored or handled,said Wall panel comprising a plurality of sheets of foraminous screenmaterial, said sheets lying in parallel relation and being secured toeach other, each of said sheets having thereon a continuous coating offireproof plastic material, the over-all thickness of each coated sheetbein not materially great r than that of the uncoated sheet.

2. .A Wa l pan l for a cham er Where explo ive are stored or handled,said wall panel comp ing a p urality of Parallel sheets of foraminousscreen material, two of said Sheets retaining therebetween and beingsecured together by a filling compound of fireproof plastic material, thov r-all thickness of the filled sheets bein not materially greater thanthat of the unfilled sheets.

3. In a building having a room adapted for containing explosives orhighly inflammable material, a wall structure for said room, comprisingin combination, an interior partition panel including two parallelclosely juxtaposed sheets of foraminous screen material, each of saidsheets having thereon a coating of fireproof material, the coating ofthe two sheets securing them together, and an exterior wall panelincluding at least two parallel spaced sheets of foraminous screenmaterial, each embedded in its own coating of translucent, shatterproofplastic material, said translucent sheets providing therebetween aninert air space and the wall formed by said sheets being less resistantto explosive forces within said room than said interior wall.

HOWARD G. PILLSBURY. ELTON B. INGERSOLL.

